The present invention is directed to spiral cores for reinforcing stress skin and other structures and, in particular, to spiral cores for reinforcing such structures comprising fiber glass insulation and the method of making such cores.
Doors, office partitions, construction panels, wall structures and the like often comprise a peripheral frame with stress skin facing sheets secured to the frame to form a hollow core structure. For certain applications, this type of structure is satisfactory. However, for many applications, the hollow core structure is not strong enough to withstand the service requirements and the structure must be reinforced. One method of reinforcing such structures is to place a cellular or honeycomb reinforcing core within the structure between the stress skin facing sheets. The honeycomb reinforcing core is sandwiched between the stress skin facing sheets providing support to the facing sheets and strengthening the overall structure.
However, these cellular or honeycomb reinforcing cores, which are normally made of wood or metal, do not provide acoustical or thermal insulation to the structure and any insulation for the structure would have to be placed within the structure in a separate operation. In addition, these cellular or honeycomb structures are uniform in structure throughout and provide uniform reinforcement across the width of the stress skin facing sheets. The cellular or honeycomb cores do not provide additional reinforcement away from the peripheral frame where the reinforcement is most needed. Accordingly, there has been a need to provide an improved reinforcing core which both insulates the structure and provides additional reinforcement closer to the middle of the facing sheet and away from the peripheral frame of the structure.